Wednesday, August 31, 2005

Homo Sapiens cold adaptations

Homo Sapiens cold adaptations

This flows from the discussion of why Western Europeans favour the bench model toilet Roman seat , compared to the squat model elsewhere .

There is a definite evolutionary advantage in sub-zero temperatures in not plonking down on your behind in a fit of absent-mindedness or fatigue . Frost-bite on the buttocks (near the anus) would be nearly always fatal . A relatively minor evolutionary change in the pelvic hip-socket would at first twinge a warning that this is an “oops” moment . Continual selection would later make this impossible . Hence the difficulty Western Europeans have in sitting cross-legged , or flat on their behind with their legs stretched out at a 90 degree angle .

This would require a small , isolated population . This is difficult to understand if there was a gradual diffusion out of Africa over a period of 3 million years .

Enter the Toba supervolcano bottleneck:
There is a good discussion at

A Quick summary : 73 000 years ago , a supervolcano at Toba in Indonesia wiped out most of homo ( circa 3 000 – 10 000 survivors) through nuclear-winter type of climate change . The survivors , using the initial tool-set of fire , stone-tools and those new-fangled clothes , then exploded into the available niches . The number of adventurous and curious in each little group were initially small . They moved in isolated groups within a short time-span into the empty areas . This gave small , isolated populations in a large area over a relatively short time-span to give explosive expression to evolutionary systems .
Note the genetic evidence of human lice that clothes came into large-scale use circa 73 000 years ago .

Let us enumerate Homo Sapiens Cold Adaptations
1. Pelvic bones make squat difficult (prevents frostbite of arse).
2. No pigmentation : white skin (Upper end of Vit D : Folic Acid balance)
3. Large size (Volume:Area)
4. Large nose (humidify air (ice and desert) , heat/cool air)
5. Subcutaneous fat (cold everywhere)
6. Haemorrhoids (cold ass)
7. Long,narrow foot (smallest temperature loss in ice. In sand , broad , short foot is better)
8. Thin lips(cold) . Thick lips help with heat dispersion .
9. Body hair : Fur compressed with clothes is a no-no , as there is more hair than air . Sparse , long , springy hair is ideal to make an air space between the clothes and the skin for insulation in cold ,northern climates . As temperatures increases southwards , clothed people are actively selected for hairlessness . I estimate the null-point to run at about 30 degree latitude , but it will depend on climate . Note that sparse hairiness is still a positive beauty aspect in northern Europe .
10. Pubic hair : humans wearing clothes were selected for springy , bushy pubic hair . This keeps clothing away from the skin for temperature control , as well as giving maximum scent-surface area.
11. Underarm hairs : temperature control on lymph nodes , pheromone and scent enhancement.
12. Skull hair : sexual dimorphism: Woman do not lose hair . Male hair-loss is selected for age and wisdom . Very old . Note Ringkoppe, Chinese head shaving , Roman Catholic Priest . Selenium shortage + social selection? I don’t know where this comes from. Any ideas?
13. Bone marrow cross-sections : cold adapted humans have round bone marrows,to minimize heat loss from the most bio-active part of the anatomy.
14. Metabolic adjustments : High-fat usage. Oily fingers . This bit is actually essential ,since it enables humans to utilize things like cheese , butter , fats , etc.
15. Dive reflex : immersing your face in cold water triggers a diving reflex . Your metabolism is lowered .

15.1 How to lose fat :

Is there an equivalent snow-reflex to the dive-reflex where the metabolism is heightened?

Yes . Not the feet (they are always cold) .

At the back of the knees.

Stand in a hot shower with the water flowing over your face and then place two ice-packs behind your knees . Keep them there until you can feel them ( about a minute) .Remove them .Then wait 10 minutes .(This 10 minutes is important , as this is the minimum time for neuron potentiation to long-term memory.) Then repeat .About 3 times should do the trick . This should increase your fat-burning metabolism . If you keep to the 10 minute regimen , this is permanent .
You have been informed .

The evolutionary toolkit :

1. Selection of the survivors ( not the fittest) . This incorporates chaotic systems .

2.Long-term : DNA mutation , sex

3.Medium-term : Dwarfism . Reduction of size by truncating the rapid-earlygrowing stage selectively . See bird-brains . A very powerful mechanism . The essential elements of an explosively exuberant organism is concentrated by inter-species conflict .
(ie the new kids on the block wipe out the competition and grow large , using the available resources . They then fight amongst themselves for the dwindling resources per kid . This concentrates their mind wonderfully . The essential parts are retained or developed , while the non-essentials are dwarfed .)

4.Short-term : epigenetic . Environmental factors can control the expression of the DNA toolkit . There is evidence that this capability is both DNA and Epigenetically controlled (ie an organism in a high-stress environment can learn to mutate faster . See Chernobyl studies.)

5.Ultra-short term : Culture (Mimicry and Language) .
For instance , Homo Florienses had a brain of about 400 cc , yet seemed to produce stone tools . One can imagine that , as dwarfism increased by generations , the most important brain-functions were kept .
Survival knowledge was stored in mimicry and language (“show and tell”).
What a terrible fate .
Almost like the civil service .

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